The present invention relates to a capacitor mold and method for using same.
In the molding of pellet capacitors, difficulty is often encountered in trying to center the capacitor pellet within the mold during molding. Failure to properly center the capacitor in the mold results in thin layers or bare spots in the protective coating that surrounds the pellet.
Therefore, a primary object of the present invention is the provision of an improved capacitor mold and method for using same.
A further object of the present invention is the provision of a capacitor mold and method for using same which centers the capacitor pellet within the mold and holds the capacitor pellet in this centered position during the molding process.
A further object of the present invention is the provision of a capacitor mold and method for using same which results in a protective coating having uniform thickness around the side walls of the pellet.
A further object of the present invention is the provision of a mold and method for using same which is economical in manufacture, durable in use, and efficient in operation.
The foregoing objects may be achieved by a combination including first and second mold dies. The two dies are movable together and are shaped to define a mold cavity therebetween. The mold cavity has a cavity anode end, a cavity cathode end, a longitudinal axis extending between the cavity anode and cathode ends, and a cavity side wall surrounding the longitudinal axis and extending between the cavity anode and cathode ends. A capacitor pellet includes an anode pellet end, a cathode pellet end and a pellet body extending therebetween. A plurality of projections extend inwardly from the cavity side wall. The projections engage the pellet body and hold the pellet body spaced away from the cavity side wall.
According to one feature of the invention the cavity side wall includes a plurality of surfaces, and at least one of the projections extends from each of the surfaces toward the longitudinal axis of the pellet.
According to another feature of the invention each of the projections is positioned adjacent the cathode end of the cavity and engages the pellet body adjacent the cathode pellet end.
According to a preferred embodiment of the invention a plurality the surfaces on the side wall comprise four surfaces.
According to a further feature of the invention the plurality of projections approximately center the pellet body within the cavity side wall so as to create a substantially uniform space between the pellet body and the cavity side wall.
According to a further feature of the invention the coating of conductive material covers the cathode pellet end and a portion of the pellet body adjacent the cathode pellet end. All of the projections engage the conductive material.
According to the method of the present invention the pellet body is placed within a molding cavity having an anode cavity end, a cathode cavity end, and a cavity side wall extending therebetween. The pellet body is retentively engaged within the cavity by a plurality of projections which extend from the cavity side wall and engage the pellet body to provide a space between the pellet body and the cavity side wall. The space extends completely around the pellet body. A molding material is used to fill the space to provide a coating on the pellet body.